JP2002246671A - Method of manufacturing magnetic detection element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve a problem that a sufficient vertical bias magnetic filed cannot be supplied to a free magnetic layer and the free magnetic layer is difficult to be made into a single magnetic domain by tapering the tip part of a second antiferromagnetic layer in the conventional exchange bias system of a magnetic detection element. SOLUTION: In a bottom-type spin bulb-like thin film element, respective layers are laminated, and a part of the second ferromagnetic layer 31 which is not covered by an electrode layer 33 and a first free magnetic layer 28 is removed with the electrode layer 33 as a mask. Thus, the left tip part 31a of the second ferromagnetic layer 31 is not tapered and a sufficient exchange connection magnetic field can be given to the first free magnetic layer 28. Consequently, the magnetization of the second free magnetic layer 30 can be made into the single magnetic domain.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic sensing element whose electric resistance changes depending on the relationship between the direction of fixed magnetization of a fixed magnetic layer and the direction of magnetization of a free magnetic layer affected by an external magnetic field. The present invention relates to a method of manufacturing a magnetic sensing element capable of increasing a longitudinal bias magnetic field and appropriately directing magnetizations of a fixed magnetic layer and a free magnetic layer in a crossing direction in a bias method.

[0002]

2. Description of the Related Art An AMR (Anisotropic Matrix) having a magnetoresistive effect element is known as a magnetoresistive effect type magnetic sensing element.
gnetoresistive) heads and GMR (Giant Magnetoresistive) heads provided with elements exhibiting a giant magnetoresistance effect. In the AMR head, the element exhibiting the magnetoresistance effect has a single-layer structure made of a magnetic material. On the other hand, G
In the MR head, the element has a multilayer structure in which a plurality of materials are stacked. There are several types of structures that produce the giant magnetoresistance effect. A spin-valve thin-film magnetic element has a relatively simple structure and a high rate of change in resistance to a weak external magnetic field.

FIG. 15 is a cross-sectional view showing a structure of an example of a conventional spin-valve thin-film magnetic element when viewed from a surface facing a recording medium.

The spin-valve thin-film magnetic element shown in FIG. 15 is a so-called bottom-type single spin-valve thin-film magnetic element in which an antiferromagnetic layer, a pinned magnetic layer, a nonmagnetic material layer, and a free magnetic layer are formed one by one. It is.

The spin-valve type thin-film magnetic element shown in FIG. 15 comprises an underlayer 6, an antiferromagnetic layer 1, a fixed magnetic layer 2, a nonmagnetic material layer 3, a free magnetic layer 4, and a protective layer 7 from below. The multilayer film 9 includes a pair of hard bias layers (permanent magnet layers) 5 and 5 formed on both sides of the multilayer film 9 and a pair of electrode layers 8 and 8 formed on the hard bias layers 5 and 5. It is configured. The track width Tw is determined by the width of the upper surface of the multilayer film 9.

Generally, the antiferromagnetic layer 1 is made of Fe-M
The n-alloy film or the Ni-Mn alloy film, the fixed magnetic layer 2 and the free magnetic layer 4 have a Ni-Fe alloy film, the non-magnetic material layer 3 has a Cu film, and the hard bias layers 5 and 5 have , Co
A Pt alloy film, a Cr film or a W film on the electrode layers 8, 8,
Ta is used for the underlayer 6 and the protective layer 7.

As shown in FIG. 15, the magnetization of the fixed magnetic layer 2 is converted into a single magnetic domain in the Y direction (the direction of the leakage magnetic field from the recording medium: the height direction) by the exchange coupling magnetic field with the antiferromagnetic layer 1. The magnetization of the free magnetic layer 4 is aligned in the illustrated X direction (track width direction) under the influence of the bias magnetic field from the hard bias layers 5,5.

That is, the magnetization of the fixed magnetic layer 2 and the magnetization of the free magnetic layer 4 are adjusted to be substantially orthogonal.

In this spin-valve thin-film element, a detection current (sense current) is applied to the fixed magnetic layer 2, the non-magnetic material layer 3, and the free magnetic layer 4 from the electrode layers 8, 8. When the direction of the leakage magnetic field from the recording medium is given in the Y direction, the magnetization of the free magnetic layer 4 changes from the X direction to the Y direction. The electric resistance changes (this is called a magnetoresistance effect) due to the relationship between the change in the magnetization direction in the free magnetic layer 4 and the fixed magnetization direction of the fixed magnetic layer 2, and the voltage based on the change in the electric resistance value is changed. Due to the change, a leakage magnetic field from the recording medium is detected.

However, the spin-valve thin-film element shown in FIG. 1 has a problem that it cannot appropriately cope with high recording density.

That is, as described above, the magnetization of the fixed magnetic layer 2 is fixed as a single magnetic domain in the Y direction in the figure, but the hard magnetic layers magnetized in the X direction are provided on both sides of the fixed magnetic layer 2. Bias layers 5 and 5 are provided. Therefore, in particular, the magnetization at both end portions of the fixed magnetic layer 2 is not fixed in the Y direction in the drawing due to the influence of the bias magnetic field from the hard bias layers 5 and 5.

Accordingly, upon receiving the magnetization of the hard bias layers 5 and 5 in the X direction, the magnetization of the free magnetic layer 4 and the magnetization of the fixed magnetic layer 2 which are single-domain in the X direction become the magnetization of the multilayer film 9. There is no orthogonal relationship near both ends. In addition, the magnetization near both ends of the free magnetic layer 4 is easily fixed because it is affected by the strong magnetization from the hard bias layers 5 and 5, and the magnetization hardly fluctuates with an external magnetic field. As shown in FIG. 7, near the side end of the multilayer film 9, a dead area with poor reproduction sensitivity is formed.

Therefore, the central region of the multilayer film 9 excluding the dead region substantially contributes to the reproduction of the recording medium, and has a sensitivity region (substantial track width) where the magnetoresistive effect is exhibited. However, it is difficult to define the width of the sensitive region with an accurate width due to variations in the dead region. Therefore, it is difficult to appropriately cope with a narrower track due to a higher recording density in the future.

FIG. 16 shows a spin-valve type thin film element improved to solve the above problem. FIG. 1
6 shows one manufacturing process. The same reference numerals as those in FIG. 15 indicate the same layers.

In this spin-valve type thin film element, both end portions 4a of the free magnetic layer 4 are partially removed, and the ferromagnetic layers 13 are formed in the removed portions.
Further, a second antiferromagnetic layer 10 and an electrode layer 8 are continuously formed on the ferromagnetic layers 13 and 13 by using a resist layer 12 for lift-off. The second antiferromagnetic layer 10 is formed of an antiferromagnetic material. The ferromagnetic layer 13 is made of, for example, Ni.
It is an Fe alloy film.

The spin-valve type thin film element shown in FIG.
In this method, a vertical bias magnetic field is applied to the free magnetic layer by a so-called exchange bias method. In the exchange bias method, the second antiferromagnetic layer 10
An exchange coupling magnetic field is generated between the ferromagnetic layer 13 and the ferromagnetic layer 13, and a longitudinal bias magnetic field in the illustrated X direction is supplied to the free magnetic layer 4 by ferromagnetic coupling between the ferromagnetic layer 13 and the free magnetic layer 4.

When this exchange bias method is used, a dead area is not formed unlike the spin-valve type thin film element shown in FIG. 15, so that the track width Tw can be accurately and easily defined in a future high recording density. Was thought to be possible.

[0018]

However, the spin valve type thin film device shown in FIG. 16 also has the following problems.

That is, as shown in FIG. 16, the tips 10a, 10a of the second antiferromagnetic layer 10 formed by using the lift-off resist layer 12 are tapered, so that the tips 10a The exchange coupling magnetic field generated between the layers 13 is very small. In particular, the thickness of the tip 10a is about 50
If it is smaller than Å, no exchange coupling magnetic field is generated. Therefore, a sufficient vertical bias magnetic field is not supplied to the free magnetic layer 4 located below the tapered tip portion 10a, and the free magnetic layer 4 between the track widths Tw is formed into a single magnetic domain due to a weak vertical bias magnetic field. This causes problems such as generation of Barkhausen noise.

Further, the magnetization of the both ends of the free magnetic layer 4 formed under the tip portion 10a tends to fluctuate with respect to an external magnetic field because it is not strongly pinned in the track width direction. Problems occur.

According to the method of controlling the magnetization of the free magnetic layer 4 by the exchange bias method, a step of generating an exchange coupling magnetic field between the first antiferromagnetic layer 1 and the fixed magnetic layer 2 is performed. Since there are two steps of generating an exchange coupling magnetic field between the ferromagnetic layer 10 and the ferromagnetic layer 13, the heat treatment temperature and the magnitude and direction of the applied magnetic field in these steps are not appropriately adjusted. Therefore, the magnetizations of the pinned magnetic layer 2 and the free magnetic layer 4 cannot be appropriately directed in the directions of crossing each other.

Accordingly, the present invention has been made to solve the above-mentioned problem, and in particular, it is possible to generate a large vertical bias magnetic field by eliminating the taper at the tip of the second antiferromagnetic layer. Moreover, it is an object of the present invention to provide a method of manufacturing a magnetic sensing element capable of appropriately directing the magnetizations of the free magnetic layer and the pinned magnetic layer to cross each other.

[0023]

According to the present invention, there is provided a method for manufacturing a magnetic sensing element, comprising the steps of (a) forming a first antiferromagnetic layer, a fixed magnetic layer, a nonmagnetic material layer, and a first Forming a stacked body by sequentially stacking a free magnetic layer, a non-magnetic intermediate layer, and a second free magnetic layer, in that order, and a second antiferromagnetic layer; Heat treatment is performed at a first heat treatment temperature while applying a first magnetic field in a direction orthogonal to the track width direction to the stacked body, and an exchange coupling magnetic field is applied to the first antiferromagnetic layer and the second antiferromagnetic layer. Is generated to fix the magnetizations of the fixed magnetic layer and the free magnetic layer in the orthogonal direction, and to change the exchange coupling magnetic field of the first antiferromagnetic layer to the exchange coupling magnetic field of the second antiferromagnetic layer. (C) in the track width direction in the step (b). A second heat treatment higher than the first heat treatment temperature while applying a second magnetic field larger than the exchange coupling magnetic field of the antiferromagnetic layer and smaller than the exchange coupling magnetic field of the first antiferromagnetic layer; Heat treating at a temperature to apply a longitudinal bias magnetic field to the free magnetic layer in a direction crossing the magnetization direction of the pinned magnetic layer; and (d) forming a pair of electrode layers on the laminate at a constant interval. And (e) removing the laminated body exposed from between the pair of electrode layers to the middle of the second free magnetic layer.

In the present invention, as shown in the above step (a), the free magnetic layer has a so-called ferri structure in which a non-magnetic intermediate layer is interposed between two magnetic layers. In the ferri structure,
The magnetizations of the first free magnetic layer and the second free magnetic layer are antiparallel to each other. When the ferrimagnetic structure is used, the magnetization state can be further stabilized.

According to the above-described manufacturing method, the second antiferromagnetic layer not covered by the electrode layer and the first antiferromagnetic layer using the pair of electrode layers formed in the step (d) as a mask are used. To a part of the free magnetic layer. According to this manufacturing method, the tip of the second antiferromagnetic layer formed on the free magnetic layer does not taper as in the related art, and the free magnetic layer has a ferrimagnetic structure. A sufficient longitudinal bias magnetic field can be supplied from the second antiferromagnetic layer to the free magnetic layer, so that the free magnetic layer can be appropriately made into a single magnetic domain, and the occurrence of side reading can be suppressed.

Therefore, according to the present invention, even in a future increase in recording density, it is possible to appropriately promote the formation of a single magnetic domain in the free magnetic layer while narrowing the track, and to appropriately suppress the occurrence of Barkhausen noise. Can be manufactured.

Next, in the present invention, it is possible to adjust the magnetizations of the free magnetic layer and the pinned magnetic layer in the direction in which they cross appropriately by the method shown in the above steps (b) and (c).

First, in the step (b), heat treatment is performed at a first heat treatment temperature to generate an exchange coupling magnetic field in the first antiferromagnetic layer and the second antiferromagnetic layer. The magnetization of both the free magnetic layer and the free magnetic layer is fixed in the first applied magnetic field direction (height direction). At this time, the exchange coupling magnetic field of the first antiferromagnetic layer is set to be larger than the exchange coupling magnetic field of the second antiferromagnetic layer. This has a structure of a so-called bottom-type spin-valve thin film element in which the first antiferromagnetic layer is formed below the second antiferromagnetic layer, or a composition ratio of the first antiferromagnetic layer. Can be achieved by appropriately adjusting

Next, in the step (c), the exchange coupling magnetic field of the second antiferromagnetic layer in the step (b) is larger than the exchange coupling magnetic field of the first antiferromagnetic layer. A second magnetic field is applied in the track width direction. The heat treatment temperature (second heat treatment temperature) at this time is higher than the first heat treatment temperature.

In this step, the magnetization of the fixed magnetic layer is
The magnitude of the second applied magnetic field is equal to the first magnitude in the step (b).
Is smaller than the exchange coupling magnetic field of the antiferromagnetic layer, and remains fixed in a direction (height direction) orthogonal to the track width direction.

On the other hand, the magnetization of the free magnetic layer depends on the direction of the applied magnetic field because the magnitude of the second applied magnetic field is larger than the exchange coupling magnetic field of the second antiferromagnetic layer in the step (b). Since the magnetic flux fluctuates in a certain track width direction and the heat treatment temperature is higher than the first heat treatment temperature, an exchange coupling magnetic field larger than that in the step (b) is generated from the second antiferromagnetic layer. Are appropriately aligned in the track width direction.

As described above, according to the method of manufacturing the magnetic sensing element of the present invention, the tip of the second antiferromagnetic layer can be made not to be tapered as compared with the related art, and the free magnetic layer can be made of ferrimagnetic material. By having such a structure, a large longitudinal bias magnetic field can be supplied to the free magnetic layer, and the single magnetic domain of the free magnetic layer can be promoted, and the magnetizations of the free magnetic layer and the pinned magnetic layer appropriately cross each other. It is possible to adjust.

Further, the above-described method for manufacturing a spin-valve thin-film magnetic element comprises the steps of: providing a first antiferromagnetic layer, a fixed magnetic layer, a nonmagnetic material layer, a free magnetic layer, Since the stacked body is formed by sequentially stacking the antiferromagnetic layers to form a stacked body and heat-treating the stacked body, when the stacked body is formed, the space between the substrate and the second antiferromagnetic layer is formed. The surface of each layer to be formed is not exposed to the atmosphere, and as in the case where the surface of each layer is exposed to the atmosphere, the surface that has been exposed to the air is cleaned by ion milling or reverse sputtering, and then the layer thereon is removed. Since it is not necessary to form, the magnetic sensing element can be easily manufactured. Further, a manufacturing method with good reproducibility can be obtained. Further, since it is not necessary to clean the surface of each layer by ion milling or reverse sputtering, there are disadvantages caused by cleaning such as contamination due to reattachment and adverse effects on generation of an exchange coupling magnetic field due to disorder of the crystal state of the surface. An excellent manufacturing method that does not cause generation can be obtained.

In the present invention, in the step (a), a pair of electrode layers of the step (d) is formed on the second antiferromagnetic layer, and the step (c) is followed by the step (c). e) A step may be performed.

In the present invention, it is preferable that the pair of electrode layers is formed using a lift-off resist layer.
By appropriately adjusting the width dimension of the lower surface of the lift-off resist layer in the track width direction, it is possible to manufacture a magnetic sensing element capable of narrowing the track even at a high recording density.

Further, in the present invention, in the step (e), the laminate may be removed partway through the non-magnetic intermediate layer. In such a case, a large longitudinal bias magnetic field is applied to the free magnetic layer having a ferrimagnetic structure under the second antiferromagnetic layer, so that the free magnetic layer can be made into a single magnetic domain, and the nonmagnetic intermediate layer is formed. It becomes a so-called backed layer, a large ΔMR (resistance change rate) can be obtained by the spin filter effect, and it is possible to manufacture a magnetic sensing element capable of coping with a higher recording density in the future.

In the present invention, the first antiferromagnetic layer and the second antiferromagnetic layer have Pt, Pd, Rh, R
u, Ir, Os, Au, Ag, Cr, Ni, Ne, A
It is preferable to use an alloy including Mn and at least one or more of r, Xe, and Kr.

In the present invention, the free magnetic layer has a laminated ferrimagnetic structure, and a vertical bias magnetic field is supplied to the second free magnetic layer constituting the free magnetic layer by an exchange bias method. When the magnetic layer is magnetized in one direction in the track width direction, RKK acting between the first free magnetic layer and the second free magnetic layer
The first free magnetic layer is magnetized antiparallel to the second free magnetic layer by the Y interaction.

In order to appropriately maintain the antiparallel magnetization state, the materials of the first free magnetic layer and the second free magnetic layer are improved so that the first free magnetic layer and the second free magnetic layer can be interposed between the first free magnetic layer and the second free magnetic layer. There is a need to increase the exchange coupling field in the working RKKY interaction.

A material often used as a magnetic material is Ni.
There is an Fe alloy. A NiFe alloy has been conventionally used for a free magnetic layer or the like because of its excellent soft magnetic properties. However, when the free magnetic layer has a laminated ferrimagnetic structure, a NiFe alloy between the first and second free magnetic layers formed of the NiFe alloy is used. The anti-parallel coupling force is not very strong.

Therefore, in the present invention, the materials of the first free magnetic layer and the second free magnetic layer are improved, and the antiparallel coupling force between the first free magnetic layer and the second free magnetic layer is increased. Due to the synergistic effect of the exchange coupling magnetic field acting between the first antiferromagnetic layer and the second free magnetic layer, both ends of the first and second free magnetic layers located on both sides in the track width direction are exposed to an external magnetic field. On the other hand, a CoFeNi alloy is used for at least one of the first free magnetic layer and the second free magnetic layer, and preferably both, in order to prevent fluctuation and to appropriately suppress the occurrence of side reading. It is. By containing Co, the above antiparallel coupling force can be strengthened.

FIG. 14 is a conceptual diagram of a hysteresis loop when the free magnetic layer has a laminated ferrimagnetic structure. For example, it is assumed that the magnetic moment per unit area of the first free magnetic layer (F1) (saturation magnetization Ms × film thickness t) is larger than the magnetic moment per unit area of the second free magnetic layer (F2). It is also assumed that an external magnetic field is applied in the right direction in the figure.

The vector sum of the magnetic moment per unit area of the first free magnetic layer and the magnetic moment per unit area of the second free magnetic layer (| Ms · t (F1) +
The composite magnetic moment per unit area, which can be obtained by Ms · t (F2) |), is constant from the zero magnetic field to a certain point even when the external magnetic field is increased. In the external magnetic field region A where the combined magnetic moment per unit area is constant, the antiparallel coupling force acting between the first free magnetic layer and the second free magnetic layer is stronger than the external magnetic field. The magnetizations of the first and second free magnetic layers are appropriately made into a single magnetic domain and maintained in an antiparallel state.

However, when the external magnetic field is further increased in the right direction in the figure, the combined magnetic moment per unit area of the free magnetic layer increases with an inclination angle. This is because the external magnetic field is stronger than the antiparallel coupling force acting between the first free magnetic layer and the second free magnetic layer, so that the first free magnetic layer and the second The magnetization of the free magnetic layer is dispersed to form a multi-domain state, and the resultant magnetic moment per unit area, which can be obtained by the vector sum, increases. In the external magnetic field region B where the combined magnetic moment per unit area increases, the antiparallel state of the free magnetic layer is no longer in a state of being collapsed. The magnitude of the external magnetic field at the starting point where the combined magnetic moment per unit area starts to increase is called a spin-flop magnetic field (Hsf).

When the external magnetic field in the right direction in the figure is further increased, the magnetizations of the first free magnetic layer and the second free magnetic layer are changed to single magnetic domains again, which is different from the case of the external magnetic field region A. Both are magnetized in the right direction in the figure, and the resultant magnetic moment per unit area in the external magnetic field region C has a constant value. The magnitude of the external magnetic field at the time when the resultant magnetic moment per unit area becomes a constant value is defined as the saturation magnetic field (H
s).

In the present invention, the CoFeNi alloy is first
When used for the free magnetic layer and the second free magnetic layer,
A magnetic field when the antiparallel state collapses as compared with the case where the NiFe alloy is used, so-called spin-flop magnetic field (Hsf)
Was found to be sufficiently large.

In the present invention, the following experiments were performed to determine the magnitude of the spin-flop magnetic field using a NiFe alloy (Comparative Example) and a CoFeNi alloy (Example) for the first and second free magnetic layers. Performed using the configuration.

Substrate / non-magnetic material layer (Cu) / first free magnetic layer (2.4) / non-magnetic intermediate layer (Ru) / second free magnetic layer (1.4). Note that the parentheses indicate the film thickness and the unit is nm.

For the first free magnetic layer and the second free magnetic layer in the comparative example, a NiFe alloy containing 80 atomic% of Ni and 20 atomic% of Fe was used.
The spin flop magnetic field (Hsf) at this time is about 59 (k
A / m).

Next, in the first free magnetic layer and the second free magnetic layer in the embodiment, the composition ratio of Co is 87 atomic%, and
Fe composition ratio is 11 atomic%, Ni composition ratio is 2 atomic%
A CoFeNi alloy consisting of At this time, the spin-flop magnetic field (Hsf) was about 293 (kA / m).

As described above, the first free magnetic layer and the second free magnetic layer use CoFe rather than using a NiFe alloy.
It has been found that the use of a Ni alloy can effectively improve the spin-flop magnetic field.

Next, the composition ratio of the CoFeNi alloy will be described. The CoFeNi alloy has a non-magnetic intermediate layer R
It has been found that the magnetostriction shifts to the positive side by about 1 × 6 ^{−6 to} 6 × 10 ⁻⁶ by using the NiFe alloy in contact with the u layer.

The magnetostriction is preferably in the range of -3 × 10 ^-6 to 3 × 10 ^-6 . The coercive force is 790 (A
/ M) or less. When the magnetostriction is large, the magnetostriction is preferably low because the film is susceptible to stress due to film formation strain and a difference in thermal expansion coefficient between other layers. Further, the coercive force is preferably low, so that the magnetization reversal of the free magnetic layer with respect to an external magnetic field can be improved.

In the present invention, when formed in a film configuration of nonmagnetic material layer / first free magnetic layer / nonmagnetic intermediate layer / second free magnetic layer, the Fe composition ratio of CoFeNi is 9 atomic% or more. Is preferably 17 atomic% or less, the composition ratio of Ni is 0.5 atomic% or more and 10 atomic% or less, and the remaining composition ratio is preferably Co. If the composition ratio of Fe is more than 17 atomic%, the magnetostriction becomes negative more than -3 × 10 ^-6 and the soft magnetic characteristics are deteriorated, which is not preferable.

When the composition ratio of Fe is less than 9 atomic%, the magnetostriction becomes larger than 3 × 10 ⁻⁶ and the soft magnetic characteristics are deteriorated.

[0056] Further, when the composition ratio of Ni is larger than 10 atomic%, the magnetostriction becomes larger than 3 × 10 ^-6,
It is not preferable because the amount of change in resistance (ΔR) and the rate of change in resistance (ΔR / R) due to diffusion of Ni between the nonmagnetic material layer and the like are reduced.

[0057] Further, when the composition ratio of Ni is less than 0.5 atomic%, the magnetostriction undesirably increases the negative than -3 × 10 ^-6.

The coercive force can be reduced to 790 (A / m) or less within the above composition range.

Next, according to the present invention, when formed in a film configuration of a non-magnetic material layer / intermediate layer (CoFe alloy) / first free magnetic layer / non-magnetic intermediate layer / second free magnetic layer, the CoFeNi Fe composition ratio is more than 7 atomic% and 15 atomic%
Hereinafter, it is preferable that the composition ratio of Ni is not less than 5 atomic% and not more than 15 atomic%, and the remaining composition ratio is Co. When the composition ratio of Fe is larger than 15 atomic%, the magnetostriction becomes −3 ×
Undesirable to deteriorate the soft magnetic properties with negatively larger than 10 ^-6.

If the composition ratio of Fe is less than 7 atomic%, the magnetostriction becomes larger than 3 × 10 ⁻⁶ and the soft magnetic characteristics are deteriorated, which is not preferable.

If the composition ratio of Ni is larger than 15 atomic%, the magnetostriction is larger than 3 × 10 ^−6, which is not preferable.

If the composition ratio of Ni is less than 5 atomic%, the magnetostriction becomes undesirably larger than -3 × 10 ^-6 .

The coercive force can be reduced to 790 (A / m) or less within the above composition range.

Since the intermediate layer made of CoFe or Co has minus magnetostriction, the intermediate layer has a smaller thickness than that of a film configuration in which the intermediate layer is not interposed between the first free magnetic layer and the nonmagnetic material layer. The Fe composition of the CoFeNi alloy is slightly reduced, and the Ni composition is slightly increased.

Also, as in the above-described film configuration, an intermediate layer made of a CoFe alloy or Co is interposed between the non-magnetic material layer and the first free magnetic layer, so that the first free magnetic layer and the non-magnetic material layer are interposed. It is preferable because the diffusion of the metal element can be more effectively prevented.

In the present invention, it is preferable that both the first free magnetic layer and the second free magnetic layer are formed of CoFeNi.

Next, preferred ranges of the heat treatment temperature and the composition of the first antiferromagnetic layer and the second antiferromagnetic layer in the steps (b) and (c) will be described.

FIG. 12 is a graph showing the relationship between the heat treatment temperature of the antiferromagnetic layer and the exchange coupling magnetic field in the bottom spin valve thin film magnetic element and the top spin valve thin film magnetic element.

The film composition of the top-type spin-valve thin-film magnetic element is such that Al ₂ O ₃ (1000)
Underlayer made of Ta, underlayer made of Ta (50), N
a free magnetic layer composed of two layers of iFe alloy (70) and Co (10), a nonmagnetic material layer composed of Cu (30), C
a pinned magnetic layer made of o (25), Pt _55.4 Mn _44.6 (3
00) and a protective layer made of Ta (50).

The bottom-type spin-valve thin-film magnetic element is composed of a base insulating layer made of Al ₂ O ₃ (1000), a base layer made of Ta (30), and Pt _55.4M on a Si substrate.
antiferromagnetic layer made of n _{44 .6} (300), consisting of two layers of Co pinned magnetic layer made of (25), Cu nonmagnetic material layer made of (26), Co (10) and an NiFe alloy (70) It has a configuration in which a free magnetic layer and a protective layer made of Ta (50) are formed in this order. The thickness in parentheses indicates the thickness of each layer, and the unit is Δ.

As is apparent from FIG. 12, the distance between the antiferromagnetic layer and the substrate is short (or the antiferromagnetic layer is disposed below the fixed magnetic layer). The exchange coupling magnetic field of the ferromagnetic layer (marked with ■) has already developed at 200 ° C., and at around 240 ° C., 4.74 × 10 ⁴ (A /
m). On the other hand, the distance between the antiferromagnetic layer and the substrate is farther than the bottom type spin valve thin film magnetic element (or the antiferromagnetic layer is disposed on the fixed magnetic layer). The exchange coupling magnetic field of the antiferromagnetic layer (marked by ◆) appears at about 240 ° C. and finally exceeds 4.74 × 10 ⁴ (A / m) at about 260 ° C.

As described above, the distance between the antiferromagnetic layer and the substrate is short (or the antiferromagnetic layer is disposed below the fixed magnetic layer). The distance between the antiferromagnetic layer and the substrate is longer than that of the bottom spin-valve thin-film magnetic element (or the top spin-valve thin-film magnetic element in which the antiferromagnetic layer is arranged on the fixed magnetic layer) Thus, it can be seen that a high exchange coupling magnetic field can be obtained at a relatively low heat treatment temperature.

The spin-valve thin film magnetic element of the present invention
A bottom-type spin-valve thin-film magnetic element in which the distance between the first antiferromagnetic layer and the substrate is short, and the second antiferromagnetic layer is formed of a material similar to the material used for the first antiferromagnetic layer. The ferromagnetic layer is located farther from the substrate than the first antiferromagnetic layer.

Therefore, the spin-valve type thin film of the present invention
In the method of manufacturing a magnetic element, for example, a first magnetic field is applied.
While the first heat treatment temperature is not lower than 220 and not lower than 245 ° C.
When the laminate is heat-treated, the first antiferromagnetic
Exchange coupling magnetic field is generated in the layer and the second antiferromagnetic layer and is fixed.
The magnetization directions of the magnetic layer and free magnetic layer can be fixed in the same direction.
You. At this time, the exchange coupling magnetic field of the first antiferromagnetic layer is minimized.
1.58 × 10 even at low ^Four(A / m) or more
And preferably 4.74 × 10^Four(A / m) or more
On the other hand, the exchange coupling magnetic field of the second antiferromagnetic layer is
The exchange coupling magnetic field of the first antiferromagnetic layer can be made smaller;
Specifically, 1.58 × 10^FourSmaller than (A / m)
it can.

Next, while applying a second magnetic field in a direction orthogonal to the first applied magnetic field, the second heat treatment temperature is raised to 250 ° C. or more and 270 ° C. or less, and the laminate is heat-treated.
The exchange coupling magnetic field of the second antiferromagnetic layer is 3.16 × 10
⁴ (A / m) or more and the second
Is larger than the exchange coupling magnetic field of the antiferromagnetic layer. Accordingly, the magnetization of the free magnetic layer changes from the state of being directed in the height direction to the direction of the track width under the influence of the exchange coupling magnetic field.

At this time, if the second applied magnetic field is made smaller than the exchange coupling magnetic field of the first antiferromagnetic layer generated by the previous heat treatment, the second antimagnetic layer will Even when a magnetic field is applied, the exchange coupling magnetic field of the first antiferromagnetic layer does not deteriorate, and the magnetization direction of the fixed magnetic layer can be kept fixed in the height direction.

As described above, according to the manufacturing method of the present invention, it is possible to appropriately adjust the magnetization of the fixed magnetic layer and the magnetization of the free magnetic layer to cross each other.

Therefore, in the above-described method for manufacturing a spin-valve thin-film magnetic element, an alloy such as a PtMn alloy having excellent heat resistance is used not only for the first antiferromagnetic layer but also for the second antiferromagnetic layer. Generating an exchange-coupling magnetic field in the second antiferromagnetic layer to align the magnetization direction of the free magnetic layer in a direction crossing the magnetization direction of the fixed magnetic layer without adversely affecting the magnetization direction of the fixed magnetic layer. Since the magnetization direction of the free magnetic layer can be aligned in the direction crossing the magnetization direction of the fixed magnetic layer, a spin-valve thin-film magnetic element having excellent heat resistance and symmetry of the reproduced signal waveform can be manufactured. It is possible to do.

According to the above experimental results, in the present invention, the first heat treatment temperature was set to 220 ° C. or higher and 245 ° C.
It is preferable to set the following. Further, it is preferable that the second heat treatment heat degree is not less than 250 ° C. and not more than 270 ° C.

Next, when the heat treatment temperature is 245 ° C. or 270 ° C.
The relationship between the composition of the antiferromagnetic layer and the exchange coupling magnetic field in the case of ° C. will be described in detail with reference to FIG.

In the figures, the marks Δ and ▲ indicate that the antiferromagnetic layer is arranged at a position farther from the substrate than the free magnetic layer (or
It shows the relationship between the composition of the antiferromagnetic layer of the top-type single spin-valve thin-film magnetic element in which the antiferromagnetic layer is disposed on the fixed magnetic layer and the exchange coupling magnetic field. The symbol ▲ in the figure shows the result of heat treatment at 245 ° C.

The circles and circles in the drawings indicate a bottom type single spin valve type in which an antiferromagnetic layer is disposed between a substrate and a free magnetic layer (or an antiferromagnetic layer is disposed below a fixed magnetic layer). The graph shows the relationship between the composition of the antiferromagnetic layer of the thin-film magnetic element and the exchange coupling magnetic field.

The top spin-valve thin-film magnetic element shown by a triangle and a triangle is made of Al on a Si substrate.
_A base insulating layer made of ₂ O ₃ (1000), a base layer made of Ta (50), a NiFe alloy (70) and Co (1).
The free magnetic layer 4, Cu (30) non-magnetic material layer made of the two layers of 0), the anti-ferromagnetic layer of Co (pinned magnetic layer 2 made of _{25), Pt m Mn t (} 300), Ta
This is a configuration in which a protective layer 220 made of (50) is formed in this order. The thickness in parentheses indicates the film thickness, and the unit is Å
It is.

[0084] On the other hand, the bottom type spin-valve film magnetic element shown in ○ mark and mark ●, on a Si substrate, Al ₂ O ₃
(1000) base insulating layer made of a base layer made of Ta (30), an antiferromagnetic layer made of Pt _m Mn _t (300),
A pinned magnetic layer made of Co (25), a non-magnetic material layer made of Cu (26), a Co (10) and NiFe alloy (7
0), a free magnetic layer composed of two layers, and a protective layer composed of Ta (50). The values in parentheses indicate the film thickness, and the unit is Δ.

In the method of manufacturing the spin-valve thin-film magnetic element of the present invention, the composition ratio of the antiferromagnetic layers of the bottom-type spin-valve thin-film magnetic element and the top-type spin-valve thin-film magnetic element shown in FIG. I have.

That is, in the spin-valve thin-film magnetic element of the present invention, which is a bottom-type spin-valve thin-film magnetic element, the composition range of the alloy used for the first antiferromagnetic layer is as follows:
The antiferromagnetic layer of the bottom type spin valve type thin film magnetic element shown in FIG. 13 is preferably the same as the antiferromagnetic layer. It is preferably the same as the antiferromagnetic layer of the valve type thin film magnetic element.

As is apparent from FIG. 13, the antiferromagnetic layer of the bottom-type spin-valve thin-film magnetic element was formed of X _m Mn.
_100-m (where X is Pt, Pd, Ir, Rh, Ru,
When the alloy is made of at least one element of Os), the composition ratio m is 46 atomic% ≦ m ≦ 5.
Preferably, it is 3.5 atomic%.

M is less than 46 atomic% or 53.5 atomic%
Is exceeded, the exchange coupling magnetic field is not more than 1.58 × 10 ⁴ (A / m) even if the first heat treatment at a heat treatment temperature of 245 ° C. is performed. This is because the crystal lattice of the X-Mn alloy becomes difficult to be ordered into an L10-type ordered lattice, and does not exhibit antiferromagnetic properties. That is, the one-way exchange coupling magnetic field is not exhibited, which is not preferable.

With the above composition range, when the second heat treatment at a heat treatment temperature of 270 ° C. is performed, about 3.16 × 10
⁴ (A / m) can be obtained an exchange coupling magnetic field of more.

A more preferable composition range of the X-Mn alloy is that m is 48.5 at% or more and 52.7 at% or less. Thus, when the first heat treatment at a heat treatment temperature of 245 ° C. is performed, an exchange coupling magnetic field of 4.74 × 10 ⁴ (A / m) or more can be obtained.

[0091] Further, the antiferromagnetic layer of the bottom type spin-valve type thin film magnetic element _{Pt m Mn 100-mn Z n} ( where, Z is
At least one element or two or more elements of Pd, Ir, Rh, Ru, and Os);
n is preferably 46 atomic% ≦ m + n ≦ 53.5 atomic%, and 0.2 atomic% ≦ n ≦ 40 atomic%. Accordingly, when the first heat treatment at a heat treatment temperature of 245 ° C. is performed,
An exchange coupling magnetic field of 58 × 10 ⁴ (A / m) or more can be obtained. A more preferred composition range of m + n is 4
It is at least 8.5 at% and at most 52.7 at%.

If n is less than 0.2 atomic%, the effect of promoting the ordering of the crystal lattice of the antiferromagnetic layer, that is, the effect of increasing the exchange coupling magnetic field is not sufficiently exhibited, which is not preferable. On the other hand, if n exceeds 40 atomic%, the exchange coupling magnetic field is undesirably reduced.

[0093] Further, the antiferromagnetic layer of the bottom type spin-valve type thin film magnetic element _{Pt q Mn 100-qj L j} ( where, L is
Au, Ag, Cr, Ni, Ne, Ar, Xe, and at least one element of Kr), q and j indicating the composition ratio are 46 atomic% ≦ q + j ≦ 5.
It is preferable that 3.5 atomic% and 0.2 atomic% ≦ j ≦ 10 atomic%.

When q + j is less than 46 atomic% or exceeds 53.5 atomic%, the exchange coupling magnetic field is 1.58 × 10 ⁴ (A / m) even when the first heat treatment at a heat treatment temperature of 245 ° C. is performed.
The following is not preferable. Further, a more preferable composition range of q + j is 48.5 at% or more and 52.7 at% or less.

On the other hand, if j is less than 0.2 atomic%, the effect of improving the unidirectional exchange coupling magnetic field by adding the element L is not sufficiently exhibited, so that it is not preferable. This is not preferable because the directional exchange coupling magnetic field decreases.

Next, as apparent from FIG. 13, the antiferromagnetic layer of the top-type spin-valve thin-film magnetic element was formed of X _m Mn.
_100-m (where X is Pt, Pd, Ir, Rh, Ru,
When the alloy is composed of at least one element of Os), m indicating the composition ratio is 49 atomic% ≦ m ≦ 5.
It is preferably 5.5 atomic%.

M is less than 49 atomic% or 55.5 atomic%
Is exceeded, the exchange coupling magnetic field is not more than 1.58 × 10 ⁴ (A / m) even if the second heat treatment at a heat treatment temperature of 270 ° C. is performed, which is not preferable. This makes it difficult for the crystal lattice of the X-Mn alloy to be ordered into an L10-type ordered lattice, and does not exhibit antiferromagnetic properties. That is, a unidirectional exchange coupling magnetic field is not exhibited, which is not preferable.

When the heat treatment temperature is set to 245 ° C. in the above composition range, it is found that the exchange coupling magnetic field of the bottom antiferromagnetic layer is lower at any composition ratio. That is, even when the first heat treatment is performed, according to the above composition ratio range, the exchange coupling magnetic field of the bottom antiferromagnetic layer can be made larger than that of the top antiferromagnetic layer.

Further, m is more preferably 49.5 atomic% or more and 54.5 atomic% or less. Thereby, 270 ° C
When the heat treatment is performed, an exchange coupling magnetic field of 3.16 × 10 ⁴ (A / m) or more can be obtained. When heat treatment at 245 ° C. is performed within this composition range, the bottom-type antiferromagnetic layer has a larger exchange coupling magnetic field than the top-type antiferromagnetic layer.

[0101] Further, the antiferromagnetic layer of the top type spin-valve film magnetic element _{Pt m Mn 100-mn Z n} ( where, Z is
At least one element or two or more elements of Pd, Ir, Rh, Ru, and Os);
n is preferably 49 at% ≦ m + n ≦ 55.5 at%, and 0.2 at% ≦ n ≦ 40 at%.

When m + n is less than 49 at% or more than 55.5 at%, the exchange coupling magnetic field is 1.58 × 10 ⁴ (A / m) even if the second heat treatment at a heat treatment temperature of 270 ° C. is performed.
The following is not preferable. M + n is 49.5 atomic%.
More preferably, it is 54.5 atomic% or less.

If n is less than 0.2 atomic%, the effect of promoting the ordering of the crystal lattice of the antiferromagnetic layer, that is, the effect of increasing the exchange coupling magnetic field, is not sufficiently exhibited. Exceeds 40 atomic%, the exchange coupling magnetic field is undesirably reduced.

[0103] Further, the antiferromagnetic layer of the top type spin-valve film magnetic element _{Pt q Mn 100-qj L j} ( where, L is
Au, Ag, Cr, Ni, Ne, Ar, Xe, and Kr, at least one element or two or more elements), q and j indicating the composition ratio are 49 atomic% ≦ q + j ≦ 5.
It is preferable that 5.5 atomic% and 0.2 atomic% ≦ j ≦ 10 atomic%.

If q + j is less than 49 atomic% or exceeds 55.5 atomic%, the exchange coupling magnetic field is 1.58 × 10 ⁴ (A / m) even if the second heat treatment at a heat treatment temperature of 270 ° C. is performed.
The following is not preferable. The more preferable range of q + j is 49.5 atomic% or more and 54.5 atomic% or less.

If j is less than 0.2 atomic%, the effect of improving the unidirectional exchange coupling magnetic field by adding the element L is not sufficiently exhibited, and it is not preferable. This is not preferable because the directional exchange coupling magnetic field decreases.

In the present invention, both the first antiferromagnetic layer and the second antiferromagnetic layer may have the same composition. In such a case, it is preferable to have the following composition ratio.

That is, the first antiferromagnetic layer and the second antiferromagnetic layer are made of X _m Mn _100-m (where X is Pt, Pd, I
m, which is the composition ratio of the first antiferromagnetic layer and the second antiferromagnetic layer, when formed of an alloy comprising at least one of r, Rh, Ru, and Os). ,
It is preferable that 49 atomic% ≦ m ≦ 53.5 atomic%.

As a result, the first heat treatment at 245 ° C.
When the heat treatment is performed, the exchange coupling magnetic field of the first antiferromagnetic layer can be increased to 1.58 × 10 ⁴ (A / m) or more, and the exchange coupling magnetic field of the first antiferromagnetic layer can be reduced to the second level. The exchange coupling magnetic field of the two antiferromagnetic layers can be made larger.

When the second heat treatment at a heat treatment temperature of 270 ° C. is performed, the exchange coupling magnetic field of the second antiferromagnetic layer is set to 1.
It can be 58 × 10 ⁴ (A / m) or more.

In a still more preferred composition range, m is 49.5.
It is not less than 52.7 at% and not less than at%. The upper limit is 5
Most preferably, it is at most 1.2 atomic%. Thereby, the exchange coupling magnetic field of the first antiferromagnetic layer at 245 ° C. can be increased, and the difference between the exchange coupling magnetic fields of the first antiferromagnetic layer and the second antiferromagnetic layer can be increased. It is possible to easily control the magnetization directions of the layer and the free magnetic layer.

[0111] Also, the first antiferromagnetic layer and the second antiferromagnetic _{layer, Pt m Mn 100-mn Z} n ( where, Z is, Pd,
At least one or two or more of Ir, Rh, Ru, and Os), m and n indicating the composition ratios are
49 atomic% ≦ m + n ≦ 53.5 atomic%, 0.2 atomic% ≦
Preferably, n ≦ 40 atomic%. Still more preferable composition range is that m is 49.5 atomic% or more and 52.7 atomic%.
It is as follows. Most preferably, the upper limit is 51.2 atomic% or less.

On the other hand, if n is less than 0.2 atomic%, the effect of improving the unidirectional exchange coupling magnetic field by adding the element Z is not sufficiently exhibited. It is not preferable because the directional exchange coupling magnetic field decreases.

The first antiferromagnetic layer and the second antiferromagnetic layer are made of Pt _q Mn _100-qj L _j (where L is Au, A
g, Cr, Ni, Ne, Ar, Xe, and Kr, at least one element or two or more elements), q and j indicating the composition ratio are 49 atomic% ≦ q + j ≦ 53.5 atomic%. , 0.2 atomic% ≦ j ≦ 10 atomic%. A more preferred composition range is that m is 49.5 atomic% or more and 52.7 atomic% or less. Most preferably, the upper limit is 51.2 atomic% or less.

On the other hand, if j is less than 0.2 atomic%, the effect of improving the unidirectional exchange coupling magnetic field by adding the element L is not sufficiently exhibited. This is not preferable because the directional exchange coupling magnetic field decreases.

The composition of the first antiferromagnetic layer and the composition of the second antiferromagnetic layer of the bottom-type spin-valve thin-film magnetic element are made different from each other within the above composition range.
By making the Mn concentration of the antiferromagnetic layer of the second layer higher than the Mn concentration of the second antiferromagnetic layer, the difference between the exchange coupling magnetic fields after the first heat treatment can be made more remarkable. The magnetization of the free magnetic layer and the magnetization of the pinned magnetic layer can be more reliably brought into the orthogonal state. In such a case, a large number of combinations that can make the difference in the exchange coupling magnetic field remarkable can be selected, and the degree of freedom in design is improved.

[0116]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the magnetic sensing element (spin-valve thin film magnetic element) of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a sectional view showing the structure of a spin-valve thin-film magnetic element according to a first embodiment of the present invention when viewed from the side facing a recording medium.

Incidentally, an inductive head for recording may be laminated on the spin valve type thin film element.

The spin-valve thin-film element shown in FIG. 1 is provided, for example, at the trailing end of a slider in a hard disk drive.

FIGS. 10 and 11 are views showing a magnetic head provided with the spin-valve thin film element of the present invention. FIG. 10 is a perspective view of the slider viewed from the side facing the recording medium, and FIG. 11 is a longitudinal sectional view taken along the line 11-11 shown in FIG. 10 and viewed from the direction of the arrow.

As shown in FIGS. 10 and 11, a GMR head h including the spin-valve thin-film magnetic element is used.
Numeral 1 is provided at the trailing end 50a of the slider 50 together with the inductive head h2 to form a thin-film magnetic head 51, which can detect and record a recording magnetic field of a magnetic recording medium such as a hard disk.

As shown in FIG. 10, rails 52a, 52a, 52a are formed on the medium facing surface 52 of the slider 50, and air grooves 52b,
52b.

As shown in FIG. 11, the GMR head h1
Are a lower shield layer 53 made of a magnetic alloy formed on an end face 50a of the slider 50, a lower gap layer 54 laminated on the lower shield layer 53, and a spin-valve thin-film magnetic element 55 exposed from the medium facing surface 52. An upper gap layer 56 covering the spin-valve thin-film magnetic element 55;
And an upper shield layer 57 that covers the upper gap layer 56.

The upper shield layer 57 is also used as the lower core layer of the inductive head h2. The upper shield layer 57 and the lower core layer may be provided separately.

The inductive head h2 is joined to the lower core layer (upper shield layer) 57, the gap layer 58 laminated on the lower core layer 57, the coil 59, and the gap layer 58 at the surface facing the recording medium. And the upper core layer 60 joined to the lower core layer 57 at the base end 60a.

On the upper core layer 60, a protective layer 61 made of alumina or the like is laminated.

The spin-valve thin-film magnetic element shown in FIG. 1 has a first antiferromagnetic layer 21 and a fixed magnetic layer 2 on an insulating substrate 20 (lower gap layer) made of Al ₂ O ₃ or the like.
2. A so-called bottom-type single spin-valve thin-film magnetic element in which a nonmagnetic material layer 23 and a free magnetic layer 24 are stacked in this order.

Further, in the embodiment of the present invention, the spin-valve thin-film magnetic element aligns the magnetization direction of the free magnetic layer 24 in a direction crossing the magnetization direction of the fixed magnetic layer 22 by an exchange bias method. is there.

The exchange bias method is suitable for a spin-valve thin film magnetic element having a narrow track width corresponding to high-density recording, as compared with a hard bias method in which the effective track width is difficult to control because of the presence of a dead area. It is a method.

The first antiferromagnetic layer 21 is composed of Pt, P
d, Ir, Rh, Ru, Ir, Os, Au, Ag, C
It is made of an alloy containing at least one or more of r, Ni, Ne, Ar, Xe, and Kr and Mn. The first antiferromagnetic layer 21 made of these alloys has a feature of being excellent in heat resistance and corrosion resistance.

The durability is good when the device is provided in a hard disk device in which the temperature of the device becomes high due to the environmental temperature in the device such as a hard disk or the Joule heat caused by the sense current flowing through the device. An excellent spin-valve thin-film magnetic element with little fluctuation of the exchange coupling magnetic field can be obtained.

Further, by forming the first antiferromagnetic layer 21 from the above alloy, the blocking temperature becomes high, and a large exchange anisotropic magnetic field is generated in the first antiferromagnetic layer 21. Therefore, the magnetization direction of the fixed magnetic layer 22 can be firmly fixed.

In particular, the first antiferromagnetic layer 21 is preferably an alloy having the following composition formula.

(1) X _m Mn _100-m where X is at least one element of Pt, Pd, Ir, Rh, Ru, and Os, and indicates a composition ratio.
Is 46 atomic% ≦ m ≦ 53.5 atomic%. M indicating a more preferable composition ratio is 48.5 atomic% ≦ m ≦ 52.7.
Atomic%. Further, the first antiferromagnetic layer 21 may be an alloy having the following composition formula.

[0135] _{(2) Pt m Mn 100-} mn Z n where, Z is, Pd, Ir, Rh, Ru , at least one or more elements of Os, m indicating the composition ratio, n Is 46 atomic% ≦ m + n ≦ 53.5 atomic%,
0.2 atomic% ≦ n ≦ 40 atomic%. M and n indicating a more preferable composition ratio are 48.5 atomic% ≦ m + n ≦ 52.
7 at%, 0.2 at% ≦ n ≦ 40 at%. Further, the first antiferromagnetic layer 21 may be an alloy having the following composition formula.

(3) Pt _q Mn _100-qj L _j where L is Au, Ag, Cr, Ni, Ne, Ar, X
e, at least one element or two or more elements of Kr, and q and j indicating the composition ratio are 46 atomic% ≦ q + j ≦
53.5 at%, 0.2 at% ≦ j ≦ 10 at%. Further, q and j indicating a more preferable composition ratio are 48.
5 atomic% ≦ q + j ≦ 52.7 atomic%, 0.2 atomic% ≦ j
≦ 10 atomic%.

The first antiferromagnetic layer 21 has a thickness of, for example, 70 °.
As a result, it is formed at 300 ° or less. The pinned magnetic layer 22 has a so-called ferrimagnetic structure formed by three layers of a first pinned magnetic layer 25, a non-magnetic intermediate layer 26, and a second pinned magnetic layer 27. With this ferri structure, the magnetization state of the fixed magnetic layer 22 can be stabilized. In order to obtain a more stable ferrimagnetic structure, the first fixed magnetic layer 25 and the second fixed magnetic layer 27 have different magnetic moments per unit area. The magnetic moment per unit area is obtained by multiplying the saturation magnetic flux density by the film thickness. For example, when the same material is used for the fixed magnetic layers 25 and 27, the magnetic moments per unit area can be different from each other by making the thicknesses different from each other. Specifically, the first pinned magnetic layer 25 is set at about 15 °,
The non-magnetic intermediate layer 26 has a thickness of about 8 ° and the second pinned magnetic layer 27
Is formed at about 20 °.

The first fixed magnetic layer 25 and the second fixed magnetic layer 27 are made of, for example, a Co film, a NiFe alloy, a CoN
It is formed of an iFe alloy, a CoFe alloy, a CoNi alloy, or the like. The nonmagnetic intermediate layer 26 is made of Ru, Rh, I
Preferably, it is formed of one or more alloys of r, Cr, Re, and Cu.

Specifically, the first fixed magnetic layer 25 and the second fixed magnetic layer 27 are preferably formed of a CoFe alloy. Thereby, the exchange coupling magnetic field in the RKKY interaction acting between the first fixed magnetic layer 25 and the second fixed magnetic layer 27 can be increased.

The first pinned magnetic layer 25 shown in FIG.
Is formed in contact with the antiferromagnetic layer 21 and heat treatment in a magnetic field generates an exchange coupling magnetic field at the interface between the first fixed magnetic layer 25 and the first antiferromagnetic layer 21.

Thus, the first fixed magnetic layer 25 is fixed in, for example, the Y direction (height direction) in the figure. On the other hand, RKK
By the Y interaction, the second fixed magnetic layer 26 is fixed in a direction opposite to the Y direction in the drawing (the direction of the surface facing the recording medium). That is, the magnetizations of the first pinned magnetic layer 25 and the second pinned magnetic layer 26 are in an antiparallel state.

The nonmagnetic material layer 23 is made of Cu, C
It is preferably formed of a conductive non-magnetic material such as r, Au, and Ag.

In the present invention, the free magnetic layer 24
Are the first free magnetic layer 28, the non-magnetic intermediate layer 29 and the second
Has a so-called ferrimagnetic structure formed by three layers of the free magnetic layer 30. The first free magnetic layer 28 and the second free magnetic layer 30 are formed of, for example, a Co film, a NiFe alloy, a CoNiFe alloy, a CoFe alloy, a CoNi alloy, or the like. The nonmagnetic intermediate layer 29 is made of Ru,
It is preferable to be formed of one or more alloys of Rh, Ir, Cr, Re, and Cu.

To obtain a more stable ferrimagnetic structure, the first free magnetic layer 28 and the second free magnetic layer 30 have different magnetic moments per unit area.
The magnetic moment per unit area is obtained by multiplying the saturation magnetic flux density by the film thickness. For example, the free magnetic layer 2
When the same material is used for 8, 30, the magnetic moments per unit area can be made different from each other by making the film thickness different from each other. Specifically, the first free magnetic layer 28 is about 20 °, the nonmagnetic intermediate layer 29 is about 8 °,
The second free magnetic layer 30 is formed at about 15 °.

As shown in FIG. 1, the upper surface of the second free magnetic layer 30 is partially shaved to form a groove 24a having a track width Tw.
Are formed. If this groove is not formed, when the thickness of the second antiferromagnetic layer 31 varies, all of the second antiferromagnetic layer 31 to be removed is not removed, and the second antiferromagnetic layer 31 is not removed at the element central portion E. This is not preferable because the second antiferromagnetic layer 31 may remain.

[0146] Flat portions 24b are formed on both sides of the groove 24a. The second antiferromagnetic layer 31 is formed on the flat portion 24b. The second antiferromagnetic layer 31 is formed of an antiferromagnetic material. In such a case, the first antiferromagnetic layer 21 may be formed of the same antiferromagnetic material, or may be formed of a different material.

Therefore, by performing the heat treatment, the second
Due to the action of the exchange coupling magnetic field generated between the antiferromagnetic layer 31 and the second free magnetic layer 30, the magnetization of the both ends D and D of the second free magnetic layer 30 It is fixed in the direction crossing the magnetization, that is, in the track width direction (the direction opposite to the X direction in FIG. 1). On the other hand, in the intermediate region E of the free magnetic layer 30, the free magnetic layer 30 is aligned in the track width direction under the influence of the bias magnetic field from the both end portions D.

An RKKY interaction acts on the first free magnetic layer 28 via the non-magnetic intermediate layer 29, whereby the magnetization of the first free magnetic layer 28 becomes
Direction (track width direction). As shown in FIG. 1, by forming the free magnetic layer 24 into a so-called ferrimagnetic structure, the two magnetic layers 28 and 3 of the free magnetic layer 24 are formed.
The magnetizations of 0 become antiparallel to each other, and become a thermally stable magnetization state. Therefore, it is possible to appropriately prevent the occurrence of Barkhausen noise, suppress the occurrence of side reading, and obtain a better ΔMR.

Note that the second antiferromagnetic layer 31 is made of Pt, Pd, Ir, R, like the first antiferromagnetic layer 21.
h, Ru, Os, Au, Ag, Cr, Ni, Ne, A
It is preferable to be made of an alloy containing Mn and at least one or more of r, Xe, and Kr.

[0150] The second antiferromagnetic layer 31 made of these alloys is characterized by having excellent heat resistance and corrosion resistance.

In particular, the second antiferromagnetic layer 31 is preferably an alloy having the following composition formula.

(1) X _m Mn _100-m where X is at least one element of Pt, Pd, Ir, Rh, Ru, and Os, and indicates a composition ratio.
Is 49 at% ≦ m ≦ 55.5 at%. More preferably, it is 49.5 atomic% or more and 54.5 atomic% or less. Further, the second antiferromagnetic layer 31 may be an alloy having the following composition formula.

[0153] _{(2) Pt m Mn 100-} mn Z n where, Z is, Pd, Ir, Rh, Ru , Os, Au, A
g, Cr and Ni are at least one or two or more elements, and m and n indicating the composition ratio are 49 atomic% ≦ m
+ N ≦ 55.5 atomic%, 0.2 atomic% ≦ n ≦ 10 atomic%
It is. The more preferable range of m + n is 49.5 atomic% or more and 54.5 atomic% or less. Further, the second antiferromagnetic layer 31 may be an alloy having the following composition formula.

(3) Pt _q Mn _100-qj L _j where L is Au, Ag, Cr, Ni, Ne, Ar, X
e, at least one or two or more elements of Kr, and q and j indicating the composition ratio are 49 atomic% ≦ q + j ≦
55.5 atomic%, and 0.2 atomic% ≦ j ≦ 10 atomic%. A more preferable range of q + j is 49.5 atomic% or more and 54.5 atomic% or less.

In the present invention, as shown in FIG. 1, an electrode layer 33 is formed on the second antiferromagnetic layer 31 via a protective layer 32 made of Ta or the like.

The electrode layers 33 are made of, for example, Au,
It is preferable to be formed of W, Cr, Ta, or the like.

In this spin-valve thin-film magnetic element, a steady current is applied to the free magnetic layer 24, the nonmagnetic material layer 23, and the fixed magnetic layer 22 from the electrode layers 33, 33, and the magnetic recording medium running in the Z direction shown in the drawing. Magnetic field leakage from
Direction, the first of the free magnetic layers 24
The magnetization direction of the free magnetic layer 28 of FIG.
It fluctuates in the direction. The electric resistance changes depending on the relationship between the change in the magnetization direction in the first free magnetic layer 28 and the magnetization direction in the second pinned magnetic layer 27, and the voltage change based on the change in resistance causes leakage from the magnetic recording medium. A magnetic field is detected.

The spin-valve thin film element according to the present invention has a track width Tw on the free magnetic layer 24.
The second antiferromagnetic layer 31 formed at intervals is formed with a sufficient film thickness without the tip portions 31a, 31a being tapered.

For this reason, a large exchange coupling magnetic field is generated between the second antiferromagnetic layer 31 and the second free magnetic layer 30 formed below the tip 31a. Further, since the free magnetic layer 24 is formed in a ferrimagnetic structure, the magnetization state of the free magnetic layer 24 is stabilized, and in particular, the magnetization of the first free magnetic layer 28 is appropriately aligned in the track width direction.
Single domain.

In the present invention, at least one of the first free magnetic layer 28 and the second free magnetic layer 30 is
A composition formula that is preferably formed of a magnetic material having the following composition is represented by CoFeNi, wherein the composition ratio of Fe is 9 atom% or more and 17 atom% or less, and the composition ratio of Ni is 0.5 atom% or more and 10 atom%. Below atomic%, the remaining composition is Co.

As a result, the exchange coupling magnetic field in the RKKY interaction generated between the first free magnetic layer 28 and the second free magnetic layer 30 can be increased. Specifically, the magnetic field when the antiparallel state collapses, that is, the spin-flop magnetic field (Hsf) can be increased to about 293 (kA / m). Therefore, the second antiferromagnetic layer 3
The magnetizations at both end portions of the first free magnetic layer 28 and the second free magnetic layer 30 located below the first free magnetic layer 28 are exchanged between the second antiferromagnetic layer 31 and the second free magnetic layer 30. By the synergistic effect with the coupling magnetic field, the pinning can be appropriately performed in the antiparallel state, and the occurrence of side reading can be suppressed.

In the present invention, both the first free magnetic layer 28 and the second free magnetic layer 30 are made of the CoFe
Preferably, it is formed of a Ni alloy. Thereby, a high spin-flop magnetic field can be obtained more stably, and the first free magnetic layer 28 and the second free magnetic layer 30 can be appropriately magnetized in an antiparallel state.

When the composition is within the above range, the magnetostriction of the free magnetic layer 24 can be kept within the range of -3 × 10 ⁻⁶ to 3 × 10 ⁻⁶ , and the coercive force can be reduced to 790 (A / m 2). )
It can be reduced below.

Further, it is appropriate to improve the soft magnetic characteristics of the free magnetic layer 24 and suppress the reduction of the resistance change rate (ΔR) and the resistance change rate (ΔR / R) due to the diffusion of Ni between the nonmagnetic material layers 23. It is possible to aim at.

As shown in FIG. 1, the inner side surfaces 31b, 31b of the second antiferromagnetic layer 31 are inclined surfaces. In the present invention, the inclined surfaces are close to the vertical direction (Z direction in the figure). It can be formed by adjusting the orientation. The inner angle θ of the inclined surface is preferably 70 ° or more and 90 ° or less.

As described above, the formation of a thicker tip portion 31a of the second antiferromagnetic layer 31 can be achieved by a manufacturing method described later.

When the manufacturing method of the present invention is used, the upper surface 3 of the second free magnetic layer 30 in the element central region E
0a is shaved, and the film thickness of this portion is smaller than that of the second free magnetic layer 30 at both end portions D.

As shown in FIG. 1, the electrode layer 33 formed on the second antiferromagnetic layer 31 is formed only on the flattened surface 31c of the second antiferromagnetic layer 31. You can see that it is. On the other hand, in FIG. 16 cited as a conventional example,
It can be seen that the electrode layer 8 extends not only on the flattened surface of the second antiferromagnetic layer 10 but also on the inclined surface.

The difference between the present invention and the conventional example is caused by the difference in the manufacturing method, and it is possible to distinguish the difference in the manufacturing method from the difference in the structure.

Next, FIG. 2 shows the structure of a spin-valve thin film element according to another embodiment. The layers denoted by the same reference numerals as those in FIG. 1 indicate the same layers as those in FIG.

The difference from FIG. 1 is that in the element central region E, the second free magnetic layer 30 is completely removed and the nonmagnetic intermediate layer 29 is exposed.

The upper surface of the non-magnetic intermediate layer 29 is partially removed to form a groove 29a. The track width Tw is determined by the width of the groove 29a. Both sides of the groove 29a are flat portions 29b, 29b. Then, a second free magnetic layer 30, a second antiferromagnetic layer 31, a protective layer 32, and an electrode layer 33 are formed on the flat portion 29b.

When only the non-magnetic intermediate layer 29 exists on the first free magnetic layer 28 as described above, in this portion,
The non-magnetic intermediate layer 29 is a back layer.
er) and a so-called spin filter effect occurs.

When the nonmagnetic intermediate layer 29 functions as a backed layer, the mean free path of + spin (up spin) electrons contributing to the magnetoresistance effect is extended, and the spin filter effect ( spin filter effect
By t), a large rate of change in resistance is obtained, and it is possible to cope with high recording density. In order to appropriately generate the spin filter effect, it is preferable that the nonmagnetic intermediate layer 29 (backed layer) is formed of Cu.

Also in this embodiment, the second antiferromagnetic layer 31
Can be formed with a large film thickness, and a large exchange coupling magnetic field can be generated between the distal end 31a of the second antiferromagnetic layer 31 and the second free magnetic layer 30. In addition, since the free magnetic layer 24 has a ferri-structure formed of three layers at both end portions D, D, the second free magnetic layer 30 and the first free magnetic layer The magnetization state of the first free magnetic layer 28 in the element center region E of the first free magnetic layer 28 is also appropriately adjusted in the X direction (track width direction). Into a single magnetic domain.
Therefore, it is possible to manufacture a magnetic sensing element that can achieve a narrow track even at a high recording density, can suppress the occurrence of Barkhausen noise, and can suppress the occurrence of side reading.

In the present invention, at least one of the first free magnetic layer 28 and the second free magnetic layer 30 is
A composition formula that is preferably formed of a magnetic material having the following composition is represented by CoFeNi, wherein the composition ratio of Fe is 9 atom% or more and 17 atom% or less, and the composition ratio of Ni is 0.5 atom% or more and 10 atom% or more. At the atomic percent or less, the remaining composition ratio is Co.

As a result, the exchange coupling magnetic field in the RKKY interaction generated between the first free magnetic layer 28 and the second free magnetic layer 30 can be increased. Specifically, the magnetic field when the antiparallel state collapses, that is, the spin-flop magnetic field (Hsf) can be increased to about 293 (kA / m). Therefore, the second antiferromagnetic layer 3
The magnetizations at both end portions of the first free magnetic layer 28 and the second free magnetic layer 30 located below the pin 1 can be appropriately pinned in an antiparallel state, and the occurrence of side reading can be suppressed.

In the present invention, both the first free magnetic layer 28 and the second free magnetic layer 30 are formed by using the CoFe
Preferably, it is formed of a Ni alloy. Thereby, a high spin-flop magnetic field can be obtained more stably.

When the composition is within the above range, the magnetostriction of the free magnetic layer 24 can be kept within the range of -3 × 10 ^-6 to 3 × 10 ^-6 , and the coercive force is 790 (A / m 2). )
It can be reduced below.

Further, it is appropriate to improve the soft magnetic characteristics of the free magnetic layer 24 and suppress the reduction of the resistance change rate (ΔR) and the resistance change rate (ΔR / R) due to the diffusion of Ni between the nonmagnetic material layers 23. It is possible to aim at.

In FIGS. 1 and 2, the fixed magnetic layer 22 is formed of a three-layer ferrimagnetic structure, but may be formed of only one magnetic layer as in the conventional case. The second pinned magnetic layer 2 of the pinned magnetic layer 22
It is preferable to form a Co film on the surface of No. 7 in contact with the nonmagnetic material layer 23. Thereby, diffusion of the metal element at the interface with the nonmagnetic material layer 23 formed of Cu can be prevented, and ΔMR can be increased. The Co film is formed at about 5 °.

FIG. 3 shows the structure of a spin-valve thin film element according to a third embodiment of the present invention. The layers denoted by the same reference numerals as those in FIG. 1 indicate the same layers as those in FIG.

The difference from FIG. 1 is that the second free magnetic layer 28
An intermediate layer 41 is provided between the magnetic layer and the non-magnetic material layer 23. The intermediate layer 41 is preferably formed of a CoFe alloy or a Co alloy. In particular, it is preferably formed of a CoFe alloy.

The formation of the intermediate layer 41 prevents diffusion of metal elements and the like at the interface with the nonmagnetic material layer 23,
In addition, the resistance change amount (ΔR) and the resistance change rate (ΔR / R) can be improved. The intermediate layer 41 is formed at about 5 °.

As described with reference to FIG. 1 and FIG. 2, if the first free magnetic layer 28 particularly in contact with the nonmagnetic material layer 23 is formed of a CoFeNi alloy having the above composition ratio, the nonmagnetic material layer 23
Between the first free magnetic layer 28 and the nonmagnetic material layer 23 because the diffusion of the metal element between
The need to form the intermediate layer 41 made of an oFe alloy or Co is less than when the first free magnetic layer 28 is made of a magnetic material that does not contain Co, such as a NiFe alloy.

However, the first free magnetic layer 28 is made of Co.
Even when the first free magnetic layer 28 and the non-magnetic material layer 23 are formed, a CoFe alloy or C
It is preferable to provide the intermediate layer 41 made of o from the viewpoint that the diffusion of the metal element between the first free magnetic layer 28 and the nonmagnetic material layer 23 can be more reliably prevented.

An intermediate layer 41 is provided between the first free magnetic layer 28 and the nonmagnetic material layer 23, and at least one of the first free magnetic layer 28 and the second free magnetic layer 30 is formed of a CoFeNi alloy. When the above, the CoFeNi
The composition ratio of Fe in the alloy is 7 atom% or more and 15 atom% or less, and the composition ratio of Ni is 5 atom% or more and 15 atom% or less,
The remaining composition ratio is preferably Co.

As a result, the exchange coupling magnetic field in the RKKY interaction generated between the first free magnetic layer 28 and the second free magnetic layer 30 can be increased. Specifically, the magnetic field when the antiparallel state collapses, that is, the spin-flop magnetic field (Hsf) can be increased to about 293 (kA / m). Therefore, the second antiferromagnetic layer 3
The magnetizations at both end portions of the first free magnetic layer 28 and the second free magnetic layer 30 located below the pin 1 can be appropriately pinned in an antiparallel state, and the occurrence of side reading can be suppressed.

In the present invention, both the first free magnetic layer 28 and the second free magnetic layer 30 are made of the CoFe
Preferably, it is formed of a Ni alloy. Thereby, a high spin-flop magnetic field can be obtained more stably.

When the composition is within the above range, the magnetostriction of the free magnetic layer 24 can be kept within the range of −3 × 10 ⁻⁶ to 3 × 10 ⁻⁶ , and the coercive force is 790 (A / m 2). )
It can be reduced below. Further, the soft magnetic characteristics of the free magnetic layer 24 can be improved.

The embodiment shown in FIG. 3 can be applied to the embodiment shown in FIG. Next, a method for manufacturing a magnetic sensing element according to the present invention will be described below with reference to the drawings. FIGS. 4 to 9 are all sectional views cut from a direction parallel to the surface facing the recording medium.

In FIG. 4, a first antiferromagnetic layer 21 is formed by sputtering on an insulating substrate 20 made of Al ₂ O ₃ or the like. The first antiferromagnetic layer 21 is made of Pt, Pd, Ir,
Rh, Ru, Os, Au, Ag, Cr, Ni, Ne, A
It is preferable to use an antiferromagnetic material made of an alloy containing Mn and at least one or more of r, Xe, and Kr.

Further, continuously, the first antiferromagnetic layer 2
A fixed magnetic layer 22, a nonmagnetic material layer 23, a free magnetic layer 24, and a second antiferromagnetic layer 31 are formed on 1.

The pinned magnetic layer 22 is formed of a first pinned magnetic layer 25, a non-magnetic intermediate layer 26, and a second pinned magnetic layer 27.
Is preferably formed in a ferri-state composed of:

In the present invention, the free magnetic layer 24
Is formed in a three-layered ferri structure of a first free magnetic layer 28, a non-magnetic intermediate layer 29, and a second free magnetic layer 30.

The first pinned magnetic layer 25, the second pinned magnetic layer 27, the first free magnetic layer 28, and the second free magnetic layer 30 are made of a Co film, a NiFe alloy, a CoNiFe alloy,
It is preferable to use an oFe alloy, a CoNi alloy, or the like. The nonmagnetic intermediate layers 26 and 29 are made of Ru, Rh, I
It is preferable to use one or more alloys of r, Cr, Re, and Cu.

In the present invention, at least one of the first free magnetic layer 28 and the second free magnetic layer 30 is
Preferably, it is formed of an oFeNi alloy. At this time, when the composition ratio of Fe in the CoFeNi alloy is 9 at.
7 atomic% or less, Ni composition ratio is 0.5 atomic% or more and 1
It is preferable that the remaining composition ratio be Co at 0 atomic% or less.

When an intermediate layer 41 made of a Co or CoFe alloy is provided between the first free magnetic layer 28 and the nonmagnetic material layer 23 as shown in FIG. 3, the first free magnetic layer 28 and the second At least one of the free magnetic layers 30 is formed of a CoFeNi alloy,
The composition ratio of Fe in the i-alloy is 7 atomic% or more and 15 atomic% or less, and the Ni composition ratio is 5 atomic% or more and 15 atomic% or less,
It is preferable that the remaining composition ratio be Co.

As a result, the exchange coupling magnetic field in the RKKY interaction generated between the first free magnetic layer 28 and the second free magnetic layer 30 can be increased. Specifically, the magnetic field when the antiparallel state collapses, that is, the spin-flop magnetic field (Hsf) can be increased to about 293 (kA / m). Therefore, the second antiferromagnetic layer 3
The magnetizations at both end portions of the first free magnetic layer 28 and the second free magnetic layer 30 located below the pin 1 can be appropriately pinned in an antiparallel state, and the occurrence of side reading can be suppressed.

In the present invention, both the first free magnetic layer 28 and the second free magnetic layer 30 are made of the CoFe
Preferably, it is formed of a Ni alloy. Thereby, a high spin-flop magnetic field can be obtained more stably.

When the composition is within the above range, the magnetostriction of the free magnetic layer 24 can be kept within the range of -3 × 10 ^-6 to 3 × 10 ^{-6 and} the coercive force is 790 (A / m 2). )
It can be reduced below. Further, the soft magnetic characteristics of the free magnetic layer 24 can be improved.

The second antiferromagnetic layer 31 is made of Pt, P
d, Ir, Rh, Ru, Os, Au, Ag, Cr, N
It is preferable to use an antiferromagnetic material made of an alloy containing Mn and at least one or more of i, Ne, Ar, Xe, and Kr.

As shown in FIG. 4, a protective layer 32 made of Ta or the like is formed on the second antiferromagnetic layer 31.

According to the present invention, the first antiferromagnetic layer 21 to the second antiferromagnetic layer 31 are continuously formed. Therefore, the surface of each layer is not exposed to the air, and the surface exposed to the air is cleaned by ion milling or reverse sputtering before forming a layer thereon, as in the case where the surface of each layer is exposed to the air. Since there is no need, it can be easily manufactured. Further, a manufacturing method with good reproducibility can be obtained. Further, since it is not necessary to clean the surface of each layer by ion milling or reverse sputtering, there are disadvantages caused by cleaning such as contamination due to reattachment and adverse effects on generation of an exchange coupling magnetic field due to disorder of the crystal state of the surface. An excellent manufacturing method that does not cause generation can be obtained. Further, in the present invention, since the film is formed continuously, the first antiferromagnetic layer 21 and the first pinned magnetic layer 25, and the second antiferromagnetic layer 31 and the second free ferromagnetic layer 31 can be formed without a cleaning step. An exchange coupling magnetic field can be appropriately generated between the magnetic layers 30.

Next, a first heat treatment step is performed in the step of FIG. First, heat treatment is performed at a first heat treatment temperature while applying a first magnetic field (Y direction in the drawing) perpendicular to the track width Tw (X direction in the drawing).
In addition, an exchange coupling magnetic field is generated in the second antiferromagnetic layer 31 to fix the magnetizations of the first fixed magnetic layer 25 and the second free magnetic layer 30 in the same direction. The exchange coupling magnetic field of the ferromagnetic layer 21 is larger than the exchange coupling magnetic field of the second antiferromagnetic layer 31.

As already described with reference to FIG. 12, it is preferable that the first heat treatment temperature is not lower than 220 ° C. and not higher than 245 ° C.

As a result, the exchange coupling magnetic field of the first antiferromagnetic layer 21 can be increased to 1.58 × 10 ⁴ (A / m) or more, and more preferably 4.74 × 10 ^{4 when the} temperature is 230 ° C. or more.
A high exchange coupling magnetic field of (A / m) or more can be obtained.

On the other hand, the exchange coupling magnetic field of the second antiferromagnetic layer 31 is smaller than the exchange coupling magnetic field of the first antiferromagnetic layer.

Next, a second heat treatment step is performed. In this step, a second heat treatment temperature higher than the first heat treatment temperature is applied while applying a second magnetic field (track width direction) perpendicular to the first magnetic field. Further, the magnitude of the second applied magnetic field is larger than the exchange coupling magnetic field of the second antiferromagnetic layer 31 in the first heat treatment step, and the magnitude of the first anti-magnetic field in the first heat treatment step is increased. It is smaller than the exchange coupling magnetic field of the magnetic layer 21.

In the present invention, the second heat treatment temperature is set to 250 ° C.
The temperature is preferably set to 270 ° C. or lower.

Thus, the exchange coupling magnetic field of the second antiferromagnetic layer 31 can be made 3.16 × 10 ⁴ (A / m) or more.
The exchange coupling magnetic field generated in the first heat treatment step can be made larger. Further, since the free magnetic layer 24 has a ferrimagnetic structure, the magnetization state can be stabilized. When the magnetization of the second free magnetic layer 30 is directed in the track width direction (the opposite direction in the X direction in the drawing) by the exchange coupling magnetic field, Due to the RKKY interaction, the magnetization of the first free magnetic layer 28 is reversed and aligned in the X direction in the figure.

At this time, the second applied magnetic field is applied to the first magnetic field.
When the second applied magnetic field is applied to the first antiferromagnetic layer 21 by making it smaller than the exchange coupling magnetic field of the first antiferromagnetic layer 21 generated during the heat treatment step, The exchange coupling magnetic field of the antiferromagnetic layer 21 does not deteriorate,
It is possible to keep the magnetization direction of the fixed magnetic layer 22 fixed in the height direction. The fixed magnetic layer 22
Has a ferrimagnetic structure, the magnetization state is stabilized, and the magnetizations of the first fixed magnetic layer 25 and the second fixed magnetic layer 27 are in an antiparallel state.

As described above, by appropriately adjusting the temperature of the two heat treatment steps and the magnitude and direction of the applied magnetic field, the magnetization directions of the fixed magnetic layer 22 and the free magnetic layer 24 can be appropriately adjusted. It can be adjusted to easily cross.

The magnitude of the exchange coupling magnetic field of the first antiferromagnetic layer 21 and the second antiferromagnetic layer 31 is greatly affected by the composition ratio of each layer. It is preferable to adjust the composition ratio when forming the layer 21 and the second antiferromagnetic layer 31.

The composition ratio has already been described with reference to FIG. 13, and the first antiferromagnetic layer 21 is made of X _m Mn.
_100-m (where X is Pt, Pd, Ir, Rh, Ru,
When formed of an alloy composed of at least one element of Os), m indicating the composition ratio is 46 atomic% ≦ m ≦
Preferably, it is 53.5 atomic%. Further, a more preferable composition range is that m is 48.5 atomic% or more and 52.7 atomic% or less.

The first antiferromagnetic layer 21 is made of Pt _m M
_{n 100-mn} Z n (where, Z is, Pd, Ir, Rh, Ru ,
At least one element or two or more elements of Os), the composition ratios m and n are set to 46 atomic% ≦ m
+ N ≦ 53.5 atomic%, 0.2 atomic% ≦ n ≦ 40 atomic%
It is preferable that A more preferred composition range of m + n is 48.5 at% or more and 52.7 at% or less.

The first antiferromagnetic layer 21 is made of Pt _qM
n _100-qj L _j (where L is Au, Ag, Cr, Ni,
Ne, Ar, Xe, and Kr, at least one element or two or more elements), q, j indicating the composition ratio
Is preferably set to 46 at% ≦ q + j ≦ 53.5 at%, and 0.2 at% ≦ j ≦ 10 at%. A more preferable composition range of q + j is 58.5 at.
It is 2.7 atomic% or less.

[0218] Also the second antiferromagnetic layer 31 X _m Mn _100-m
(Where X is an alloy composed of at least one element of Pt, Pd, Ir, Rh, Ru, and Os), m indicating a composition ratio is 49 atomic% ≦ m ≦ 55.
Preferably, it is 5 atomic%. Also more preferable m
Is 49.5 atomic% or more and 54.5 atomic% or less.

[0219] Also the second antiferromagnetic layer 31 Pt _m M
_{n 100-mn} Z n (where, Z is, Pd, Ir, Rh, Ru ,
When at least one element or two or more elements of Os are formed, m and n indicating the composition ratio are set to 49 atomic% ≦ m
+ N ≦ 55.5 atomic%, 0.2 atomic% ≦ n ≦ 40 atomic%
It is preferable that Further, m + n is more preferably 49.5 atomic% or more and 54.5 atomic% or less.

The second antiferromagnetic layer 31 is made of Pt _qM
n _100-qj L _j (where L is Au, Ag, Cr, Ni,
Ne, Ar, Xe, and Kr, at least one element or two or more elements), q, j indicating the composition ratio
Is preferably 49 at% ≦ q + j ≦ 55.5 at%, and 0.2 at% ≦ j ≦ 10 at%. Note that q + j
Is more preferably 49.5 atomic% or more and 54.5 atomic% or less.

In the present invention, the composition of both the first antiferromagnetic layer 21 and the second antiferromagnetic layer 31 may be the same. In such a case, it is preferable to have the following composition ratio.

[0222] That is the first antiferromagnetic layer 21 and the second antiferromagnetic layer _{31, X m Mn 100-m} ( where, X is, Pt,
When formed of an alloy made of at least one element of Pd, Ir, Rh, Ru, and Os), the composition ratio of the first antiferromagnetic layer 21 and the second antiferromagnetic layer 31 is shown. It is preferable that m is 49 atomic% ≦ m ≦ 53.5 atomic%. In a still more preferred composition range, m is 49.5.
It is not less than 52.7 at% and not less than at%. The upper limit is 5
Most preferably, it is at most 1.2 atomic%.

[0223] Also, the first antiferromagnetic layer 21 and the second antiferromagnetic layer _{31, Pt m Mn 100-m} -n Z n ( where, Z
Is composed of at least one element or two or more elements of Pd, Ir, Rh, Ru, and Os), the composition ratio m, n is set to 49 atomic% ≦ m + n ≦ 53.5 atomic%,
It is preferable that 0.2 atomic% ≦ n ≦ 40 atomic%.
In a still more preferred composition range, m is 49.5 atomic% or more and 52.7 atomic% or less. The upper limit is 51.2 atomic%.
It is most preferred that:

The first antiferromagnetic layer 21 and the second antiferromagnetic layer 31 are made of Pt _q Mn _100-qj L _j (where L is
When formed of Au, Ag, Cr, Ni, Ne, Ar, Xe, and Kr, at least one element or two or more elements), q and j indicating the composition ratio are 49 atomic% ≦ q + j ≦ 5.
It is preferable that 3.5 atomic% and 0.2 atomic% ≦ j ≦ 10 atomic%. Still more preferred composition range is m = 49.
At least 5 atomic% and at most 52.7 atomic%. Most preferably, the upper limit is 51.2 atomic% or less.

The composition of the first antiferromagnetic layer 21 is as follows:
The composition of the second antiferromagnetic layer 31 is changed, for example,
The Mn concentration of the antiferromagnetic layer 21 of the second
By making the concentration higher than the concentration, the difference between the exchange coupling magnetic fields after the first heat treatment can be made more remarkable, and the magnetizations of the free magnetic layer 24 and the pinned magnetic layer 22 can be more reliably changed to the orthogonal state after the second heat treatment. It is possible to do. If it also takes,
A large number of combinations that can make the difference in exchange coupling magnetic field remarkable can be selected, and the degree of freedom in design is improved.

Within the composition range described above, when the first heat treatment is performed, the exchange coupling magnetic field of the first antiferromagnetic layer 21 can be increased, and the first antiferromagnetic layer 21
Can be made larger than the exchange coupling magnetic field of the second antiferromagnetic layer 31, and when the second heat treatment is performed,
The exchange coupling magnetic field of the second antiferromagnetic layer 31 can be made larger than the exchange coupling magnetic field.

Accordingly, the magnetization of the fixed magnetic layer 22 and the free magnetic layer 24 can be appropriately orthogonalized.

Next, in the present invention, a lift-off resist layer 40 is formed on the protective layer 32 as shown in FIG. The variation of the width dimension T1 of the lower surface of the resist layer 40 is as follows.
The size of the track width Tw is determined. Therefore, in order to realize a narrower track with a higher recording density in the future, it is preferable to form the width dimension T1 as small as possible.

The resist layer 40 has cutouts 40a, 40a on the left and right of the track width.

Therefore, as shown in FIG. 6, when the electrode layer 33 is formed by sputtering on the protective layer 32 on both sides of the resist layer 40, the inner tip 33a of the electrode layer 33 is formed below the notch 40a. You. The inner end 33a of the electrode layer 33 has an inclined surface or a curved surface due to a shadow effect.

On the resist layer 40, an electrode material layer 33b is formed by sputtering. Then, the resist layer 40 is removed.

As a result, the spin-valve type thin film element is formed as shown in FIG.
The state shown in is shown. Next, in a step shown in FIG. 7, a pair of electrode layers 3 having an interval of a width dimension T1 are formed on the protective layer 32.
Using the masks 3 and 33 as masks, the protective layer 32, the second antiferromagnetic layer 31, and a part of the first free magnetic layer 30 exposed in the width dimension T1 are removed by an anisotropic etching method such as RIE. I do. It is indicated by the dotted line. Thus, the spin-valve type thin-film element of FIG. 1 is completed.

Further, the first free magnetic layer 30 is completely removed, and a part of the non-magnetic intermediate layer 29 is further removed by the above-mentioned etching. It is indicated by the dashed dot.
Thus, the spin-valve thin-film element of FIG. 2 is completed.

As described above, in the present invention, a film is continuously formed from the first antiferromagnetic layer 21 to the second antiferromagnetic layer 31.
Further, by using the pair of electrode layers 33 formed using the lift-off resist layer 40 as a mask, unnecessary second antiferromagnetic layers 31 between the electrode layers 33 are removed, and the remaining second antiferromagnetic layer 31 is removed. The tip 31a of the second antiferromagnetic layer 31 does not taper as in the prior art, and a sufficient exchange coupling magnetic field is generated between the tip 31a and the second free magnetic layer 30 formed thereunder. Is maintained, and the first free magnetic layer 28 can be appropriately made into a single magnetic domain.

As shown in FIG. 7, the inner tip surface 33a of the electrode layer 33 is inclined or curved, so that the second antiferromagnetic layer 31 formed thereunder follows the inclined surface. The inner front end surface 31b is also easily inclined. However, with the method of digging with anisotropic etching,
This inclined surface can be formed at an angle close to vertical (Z direction in the figure), and it is possible to appropriately prevent the tip portion 31b of the second antiferromagnetic layer 31 from tapering.

According to the above-described manufacturing method, the track width Tw can be accurately determined according to the width of the groove 24a formed by etching.

Further, the second anti-ferromagnetic layer 31 does not remain at the center of the element, and the magnetic moment of the second free magnetic layer 30 rotates smoothly against a weak leakage magnetic field from the magnetic recording medium. A spin-valve type thin film element can be manufactured.

According to the manufacturing method described above, the electrode layer 33 is formed on the flattened surface 31 c of the second antiferromagnetic layer 31.
It will be formed only on top.

FIG. 8 and FIG. 9 are process diagrams showing another manufacturing method of the present invention. In FIG.
After stacking the layers up to the protective layer 32, the electrode layer 33 is formed by sputtering using the lift-off resist layer 40. After the resist layer 40 is removed, in the step shown in FIG. 9, an exchange coupling magnetic field is generated in the first antiferromagnetic layer 21 and the second antiferromagnetic layer 31 by performing the two heat treatment steps described above. Thus, the magnetizations of the fixed magnetic layer 22 and the free magnetic layer 24 are made orthogonal.

Thereafter, an etching step is performed using the electrode layer 33 shown in FIG. 7 as a mask. Also according to this manufacturing method, it is possible to prevent the tip portion 31a of the second antiferromagnetic layer 31 from tapering.

Finally, the action of the sense current magnetic field of the spin-valve thin film element according to the present invention will be described.

In the spin-valve thin-film magnetic element shown in FIG. 1, a second fixed magnetic layer 27 is formed below the nonmagnetic material layer 23. In this case, the direction of the sense current magnetic field is adjusted to the magnetization direction of the one of the first fixed magnetic layer 25 and the second fixed magnetic layer 27 having the larger magnetic moment.

For example, the magnetic moment per unit area of the second fixed magnetic layer 27 is larger than the magnetic moment per unit area of the first fixed magnetic layer 25, and the magnetic moment per unit area of the second fixed magnetic layer 27 is larger. It is assumed that the magnetic moment per area is oriented in a direction opposite to the illustrated Y direction (left direction in the figure). In such a case, the magnetic moment per unit area of the first pinned magnetic layer 25 and the second pinned magnetic layer 27
The combined magnetic moment per unit area obtained by adding the magnetic moment per unit area is directed in the direction opposite to the Y direction in the figure (left direction in the figure).

Then, a sense current flowing from the nonmagnetic material layer 23 as a center flows from the right to the left in the figure, and the sense current magnetic field formed at this time is below the nonmagnetic material layer 23 in the Y direction in the figure. In this case, the direction of the combined magnetic moment per unit area of the fixed magnetic layer 22 and the direction of the sense current magnetic field can be matched.

Thus, the first pinned magnetic layer 25 and the second
Exchange coupling magnetic field (RKKY) acting between the fixed magnetic layers 27 of the
The interaction is amplified, and the antiparallel state of the magnetization of the first fixed magnetic layer 25 and the magnetization of the second fixed magnetic layer 27 can be more thermally stabilized.

In particular, when a sense current of 1 mA flows, about 2.
It has been found that a sense current magnetic field of about 37 × 10 ³ (A / m) is generated and the element temperature rises by about 10 ° C. Further, the number of rotations of the recording medium is 10,000 rpm
The temperature in the apparatus rises up to about 100 ° C. due to the increase in the number of revolutions. Therefore, for example, when a sense current of 10 mA flows, the element temperature of the spin-valve thin-film magnetic element rises to about 200 ° C., and the sense current magnetic field also becomes 2.37 × 10 ⁴ (A /
m).

In the case where the sensing current flows at a very high environmental temperature and a large sense current flows, the first
The direction of the combined magnetic moment per unit area, which can be determined by adding the magnetic moment per unit area of the fixed magnetic layer 25 and the magnetic moment per unit area of the second fixed magnetic layer 27, and the sense current magnetic field Is opposite, the antiparallel state between the magnetization of the first fixed magnetic layer 25 and the magnetization of the second fixed magnetic layer 27 is easily broken.

In order to withstand high environmental temperatures, an antiferromagnetic material having a high blocking temperature is used as the first antiferromagnetic layer 21 in addition to adjusting the direction of the sense current magnetic field. There is a need. Therefore, in the present invention, the above alloy having a high blocking temperature is used.

From the above, if an attempt is made to increase the amount of sense current to increase the reproduction output in order to cope with the increase in recording density, the sense current magnetic field also increases accordingly. However, in the embodiment of the present invention, The sense current magnetic field is
Since the effect of amplifying the exchange coupling magnetic field acting between the first fixed magnetic layer and the second fixed magnetic layer is brought about, the first fixed magnetic layer and the second fixed magnetic layer are increased by increasing the sense current magnetic field. Becomes more stable.

Even in the case of a single spin-valve thin film magnetic element in which the fixed magnetic layer is formed as a single layer, the direction of the sense current magnetic field formed by applying the above-described sense current and the fixed magnetic By matching the magnetization direction of the layer, the magnetization of the fixed magnetic layer can be thermally stabilized.

The magnetic detecting element according to the present invention can be used for a thin-film magnetic head for a hard disk drive, a magnetic sensor, and the like.

[0252]

As described above in detail, according to the method of manufacturing the magnetic sensing element of the present invention, in the bottom type spin valve type thin film element, the first antiferromagnetic layer and the second antiferromagnetic layer Are continuously formed, so that the surface of each layer formed between the substrate and the second antiferromagnetic layer does not come into contact with the atmosphere. In addition, since it is not necessary to clean the surface exposed to the atmosphere by ion milling or reverse sputtering and then form a layer thereon, the magnetic sensing element can be easily manufactured. Further, a manufacturing method with good reproducibility can be obtained. Further, since it is not necessary to clean the surface of each layer by ion milling or reverse sputtering, there are disadvantages caused by cleaning such as contamination due to reattachment and adverse effects on generation of an exchange coupling magnetic field due to disorder of the crystal state of the surface. An excellent manufacturing method that does not cause generation can be obtained.

According to the manufacturing method of the present invention, the second
A pair of electrode layers formed on the anti-ferromagnetic layer of the first layer is used as a mask, and one of the second anti-ferromagnetic layer exposed between the electrode layers and the second free magnetic layer of the ferrimagnetic free magnetic layer By removing the portion up to the portion by etching, the tip of the remaining second antiferromagnetic layer can be prevented from tapering as in the related art, and the thickness of the tip can be increased. Therefore, a large exchange coupling magnetic field can be generated between the second free magnetic layer and the second antiferromagnetic layer.

In addition, according to the present invention, since the free magnetic layer has a ferrimagnetic structure, the magnetization state of the first free magnetic layer substantially contributing to a change in magnetoresistance can be stabilized, and It is possible to manufacture a magnetic sensing element capable of appropriately forming the free magnetic layer into a single magnetic domain, appropriately suppressing the occurrence of Barkhausen noise, and suppressing the occurrence of side reading.

In the present invention, the magnetization direction of the pinned magnetic layer in contact with the first antiferromagnetic layer and the magnetization direction of the free magnetic layer in contact with the second antiferromagnetic layer are determined by the temperature of the heat treatment and the magnitude of the applied magnetic field. By appropriately adjusting the height and direction, it is possible to easily and properly crossover and to manufacture a magnetic sensing element capable of obtaining a stable magnetoresistance effect.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a structure of a magnetic sensing element (spin-valve thin-film magnetic element) according to a first embodiment of the present invention when viewed from a surface facing a recording medium;

FIG. 2 is a cross-sectional view illustrating a structure of a spin-valve thin-film magnetic element according to another embodiment of the present invention when viewed from a surface facing a recording medium;

FIG. 3 is a cross-sectional view illustrating a structure of a spin-valve thin-film magnetic element according to another embodiment of the present invention when viewed from a surface facing a recording medium;

FIG. 4 is a process diagram showing a method for manufacturing a magnetic sensing element of the present invention.

FIG. 5 is a process drawing performed after FIG. 4;

FIG. 6 is a process drawing performed after FIG. 5,

7 is a process drawing performed after FIG. 6,

FIG. 8 is a process diagram showing another method for manufacturing a magnetic sensing element according to the present invention;

9 is a process drawing performed after FIG. 8,

FIG. 10 is a perspective view of a slider equipped with a magnetic sensing element according to the present invention, as viewed from a surface facing a recording medium;

FIG. 11 is a longitudinal sectional view of the thin-film magnetic head taken along line 11-11 shown in FIG. 10;

FIG. 12 is a graph showing a relationship between a heat treatment temperature and an exchange coupling magnetic field in a bottom type spin valve thin film element and a top type spin valve thin film element.

FIG. 13 is a graph showing the relationship between the Pt concentration (atomic%) of the exchange coupling magnetic field of the PtMn alloy and the exchange coupling magnetic field.

FIG. 14 is a conceptual diagram of a hysteresis loop of the free magnetic layer when the free magnetic layer has a laminated ferrimagnetic structure;

FIG. 15 is a cross-sectional view of a conventional magnetic sensing element viewed from a surface facing a recording medium;

FIG. 16 is a cross-sectional view showing one step of another magnetic sensing element.

[Explanation of symbols]

 Reference Signs List 20 insulating substrate 21 first antiferromagnetic layer 22 fixed magnetic layer 23 nonmagnetic material layer 24 free magnetic layer 25 first fixed magnetic layer 26, 29 nonmagnetic intermediate layer 27 second fixed magnetic layer 28 first free Magnetic layer 30 Second free magnetic layer 31 Second antiferromagnetic layer 32 Protective layer 33 Electrode layer 40 Lift-off resist layer

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Masaji Saito 1-7 Yukitani Otsuka, Ota-ku, Tokyo In-house Alps Electric Co., Ltd. (72) Inventor Kenichi Tanaka 1-7 Yukitani Otsuka, Ota-ku, Tokyo Alps Electric Co., Ltd. In-house (72) Inventor Yosuke Ide 1-7 Yukiya Otsuka, Ota-ku, Tokyo Alps Electric Co., Ltd. In-house F-term (reference) 5D034 BA03 CA05 5E049 AA04 AC05 BA16 DB11 GC06

Claims (11)

[Claims] 1. A method for manufacturing a magnetic sensing element, comprising the following steps. (A) On a substrate, a first antiferromagnetic layer, a fixed magnetic layer, a nonmagnetic material layer, a first free magnetic layer, a nonmagnetic intermediate layer, and a second free magnetic layer are stacked in this order from below. Forming a laminate by sequentially laminating a free magnetic layer and a second antiferromagnetic layer; and (b) applying a first magnetic field to the laminate in a direction perpendicular to the track width direction. Heat treatment at a first heat treatment temperature to generate an exchange coupling magnetic field in the first antiferromagnetic layer and the second antiferromagnetic layer so that the magnetizations of the pinned magnetic layer and the free magnetic layer are orthogonal to each other. Fixing the exchange coupling magnetic field of the first antiferromagnetic layer larger than the exchange coupling magnetic field of the second antiferromagnetic layer, and (c) in the track width direction. Greater than the exchange coupling magnetic field of the second antiferromagnetic layer in the step, and
Heat treatment at a second heat treatment temperature higher than the first heat treatment temperature while applying a second magnetic field smaller than the exchange coupling magnetic field of the antiferromagnetic layer of FIG. Applying a longitudinal bias magnetic field in a direction crossing the direction; (d) forming a pair of electrode layers at a predetermined interval on the laminate; and (e) exposing from the pair of electrode layers Removing the laminated body to the middle of the second free magnetic layer, 2. In the step (a), a pair of electrode layers in the step (d) is formed on the second antiferromagnetic layer, and the step (c) is performed after the step (c). The method for manufacturing a magnetic sensing element according to claim 1, wherein 3. The method according to claim 1, wherein the pair of electrode layers is formed using a lift-off resist layer. 4. The method for manufacturing a magnetic sensing element according to claim 1, wherein in the step (e), the laminated body is removed to a part of the non-magnetic intermediate layer. 5. The method according to claim 1, wherein the first antiferromagnetic layer and the second antiferromagnetic layer are formed of Pt, Pd, Rh, Ru, Ir, Os,
2. An antiferromagnetic material containing Mn and at least one or more of Au, Ag, Cr, Ni, Ne, Ar, Xe, and Kr.
5. The method for manufacturing a magnetic sensing element according to any one of claims 4 to 4. 6. The method of manufacturing a magnetic sensing element according to claim 1, wherein at least one of the first free magnetic layer and the second free magnetic layer is formed of a magnetic material having the following composition. Method. The composition formula is represented by CoFeNi, and the composition ratio of Fe is not less than 9 atomic% and not more than 17 atomic%.
The composition ratio of Ni is 0.5 atomic% or more and 10 atomic% or less,
The remaining composition ratio is Co. 7. The method according to claim 1, wherein an intermediate layer made of a CoFe alloy or Co is formed between the nonmagnetic material layer and the first free magnetic layer. 8. The method according to claim 7, wherein at least one of the first free magnetic layer and the second free magnetic layer is formed of a magnetic material having the following composition. The composition formula is represented by CoFeNi, and the composition ratio of Fe is 7
The composition ratio of Ni is not less than 5 atomic% and not more than 15 atomic%, and the remaining composition ratio is Co. 9. The structure according to claim 6, wherein both the first free magnetic layer and the second free magnetic layer are formed of the CoFeNi.
Or a method for manufacturing a magnetic sensing element according to item 8. 10. The method for manufacturing a magnetic sensing element according to claim 1, wherein the first heat treatment temperature is set to 220 ° C. or higher and 245 ° C. or lower. 11. The method for manufacturing a magnetic sensing element according to claim 1, wherein the second heat treatment temperature is set to 250 ° C. or higher and 270 ° C. or lower.